Sealing compounds of this type are extensively used in the building industry both on the inside and also on the outside for sealing off of building and expansion joints. Such a sealing compound is described in DE-OS 29 08 036, in which at least a part of the silicone compounds, which are used therein and are not capable of reaction, is replaced while maintaining the reactive polysiloxanes and instead organic alkylaromatic compounds are added, which each have a molecular weight of over 200. Whereas the use, for example, of a paraffinic hydrocarbon oil is not considered to be advantageous because the sealing compounds created therewith are unstable and exude during hardening.